Path: utzoo!attcan!uunet!munnari.oz.au!mel.dit.csiro.au!yarra!bohra.cpg.oz.au!als
From: als@bohra.cpg.oz (Anthony Shipman)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Trying 25MHz? (Speedup 386SX from 16MHz to 20MHz: SUCCESS!)
Summary: this will shorten the life of your machine
Message-ID: <1991Jan24.101423.29351@bohra.cpg.oz>
Date: 24 Jan 91 10:14:23 GMT
References: <1991Jan22.160249.5110@d.cs.okstate.edu>
Organization: Software Division, Computer Power Group
Lines: 26

In article <1991Jan22.160249.5110@d.cs.okstate.edu>, ong@d.cs.okstate.edu (ONG ENG TENG) writes:
> Well, a certain Mr. M (thank you) from Finland told me that his friend
> successfully sped his 16MHz 286 up to 25MHz with a small fan.
> Hhhhmmm... beside the CPU that is warm (at 20MHz), the other chips
> seems pretty cool.  The C&T chips, the other decrete components, DRAM's,
> seems OK.  The only thing that is hotter than the CPU is the *big* serial
> chip on my multi-serial card (that's the one chip you have to add for
> an extra serial port, I got 4 on mine for 4 serial ports).  Anybody 
> wanna stop me (yeah, like you would stop the astronunts (sp?) from going
> to Mars!)?


A general rule of thumb for silicon technology is that each 10 degree Celsius 
rise in chip temperature halves the lifetime of the chip. (So a 20 degree rise
reduces it by a factor of 4 etc.)

Also the chip temperature can be quite a bit higher than the package surface
temperature with a safe maximum of around 125 deg C for quality parts.

Aside from those the reliability of the circuitry may be reduced i.e. more soft
errors or greater chance of mysterious crashes.
-- 
Anthony Shipman                               ACSnet: als@bohra.cpg.oz.au
Computer Power Group
19 Cato St., East Hawthorn,
Melbourne, Australia
D